The phrase for this reason
(Gk διὰ τοῦτο/dia touto—not translated in ESV; NAS: for this reason
) can, strictly speaking, refer either backward or forward. In other words, the reason
that is referenced in the phrase may be something that has already been mentioned, or which is about to be mentioned. In the present instance, the reason
to which this phrase points is the reason for Paul’s thanksgiving. Most commentators assume that the phrase points forward, implying that the Thessalonians’ acceptance of the gospel is the reason for Paul’s thanksgiving. However, very few reasons are given for interpreting the phrase in this way.1,2,3
Although the phrase for this reason
(διὰ τοῦτο/dia touto) can refer forward, it is far more common for it to refer backward, especially in Paul’s writings (see Romans 1:26; Romans 4:16; 1 Corinthians 4:17; Ephesians 1:15; Colossians 1:9; 1 Thessalonians 3:5; 2 Thessalonians 2:11; 1 Timothy 1:16; 2 Timothy 2:10; Philemon 1:15).4 The phrase usually signals a new development in the discourse, a development which follows logically from what has gone before.5 This understanding of for this reason
fits very well in the present context. Paul was concerned to demonstrate to the Thessalonians that the message he had preached was the gospel of God (note especially 1 Thessalonians 2:2, 1 Thessalonians 2:4, 1 Thessalonians 2:8, 1 Thessalonians 2:9). It is perfectly logical, therefore, that he would bring this passage to a climax by thanking God that the Thessalonians had accepted his message as it actually is, the word of God.
Such an expression of thanks would also have the effect of encouraging the Thessalonians’ faith.
This interpretation can be summarized by paraphrasing 1 Thessalonians 2:13 as follows:
Seeing that the message we brought you was the gospel of God, we thank him continually because you accepted that message not as the word of men but as it actually is—the word of God—which is at work in you who believe.
13 And we also thank God constantly for this, that when you received the word of God, which you heard from us, you accepted it not as the word of men but as what it really is, the word of God, which is at work in you believers.